Lecture 18 - Nicotine 2 Flashcards
(14 cards)
How does nicotine test exposure models?
Nicotine offers a convenient way to study a substance addiction
It is a legal drug that is widely available, and can be administered in it pure form as a tablet, vapour etc.
What are habit-based accounts of addiction behaviour?
Behaviour becomes automatic, triggered by cues, insensitive to outcomes
Stimulus-Response (S-R) theory
Incentive Salience Theory, Attentional Bias
Outcome Devaluation Studied
What is stimulus-response habit?
Reinforcement model = through associative learning, drug associated cues and contexts acquire the capacity to motivate drug seeking and taking behaviour
Cycle between reinforcing stimulus, drug-related stimulus e.g. sight/smell of tobacco smoke and drug-seeking response e.g. buying cigarette and lighting up
Addict as a machine, behaviour automatically controlled by external cues without any thought for the consequences
Drug-induced dopamine activity reinforces the synaptic connection between drug cues and the drug-seeking response that produced the drug
As a consequence of this change in synaptic strength, drug cues elicit the drug seeking response directly
What is outcome devaluation?
Procedure:
Phase 1: Instrumental Training = rats are trained to press a lever to receive food pellets. (Establishes a goal-directed action-outcome association)
Phase 2: Outcome Devaluation = in a different environment, rats are given free access to the same food until they are satiated. (Reduces the current value of the food outcome)
Phase 3: Extinction Test = rats are placed back in the original context and allowed to press the lever, but no food is delivered. (Measures whether lever pressing persists despite devaluation)
How do you interpret the extinction test?
If responding decreases → behaviour is goal-directed: Controlled by an outcome representation, animals adjust their actions based on the current value of the outcome.
(“If I press, I get food, but I’m full now, so I won’t.”)
If responding persists → behaviour has become habitual: Controlled by stimulus-response (S-R) associations, responding is insensitive to changes in outcome value.
(– “See lever, press lever,” regardless of outcome.)
What was the procedure of Dickinson’s (1985) experiment?
Rats trained to press one lever for sucrose, one for alcohol
One reward devalued via lithium chloride (induced sickness)
Rats then tested in extinction (no rewards delivered)
Prediction:
If behaviour is goal-directed, rats should press less for the devalued reward
If behaviour is habitual, rats will continue pressing despite devaluation
What were the results of Dickinson’s (1985) experiment?
Sucrose lever: pressing decreased → behaviour goal-directed
Alcohol lever: pressing unchanged → behaviour habitual
Food-seeking involved an expectation of outcome value
Alcohol-seeking was stimulus-driven → automatic, insensitive to consequences
Suggests alcohol-seeking behaviour (and by extension other addictive behaviours) may become habitual more quickly
What is incentive salience theory?
Elaboration of habit theory (Robinson and Berridge, 2003)
Proposes that drug cues acquire the capacity to capture attention (through Pavlovian conditioning) – attentional bias
Attention results in engagement of thoughts about the drug and drug use, which in turn causes drug users to initiate drug seeking/taking
Addiction is driven not just by pleasure (“liking”), but by an intense motivation to seek drugs (“wanting”)—even when the pleasure fades
Over time, drug-related cues (e.g., smell, location) become sensitized and trigger strong “wanting,” even if “liking” is reduced
Explains why people continue to seek drugs despite no longer enjoying them—a hallmark of compulsive use
What is attentional bias?
Simple target detection (Sayette & Hufford, 1994) and change detection tasks (Jones et al., 2002) are easier for those with drug dependency if image relates to drug-use
Eye tracking (Rosse et al., 1993) eye-gaze draw more easily to drug-related cues
Stroop task (Gross et al., 1993) - those with drug dependency are slower to name the colour of drug-related words e.g. CIGARETTE, VODKA, SHOOT UP, LINE
Greater Stroop attentional bias is associated with poorer treatment outcome in those addicted to various drugs including: Tobacco (Waters, 2003), Alcohol (Cox, 2002, 2007), Heroin (Marissen,2006), Cocaine (Carpenter, 2006)
What are goal-directed accounts of addiction behaviour?
Behaviour is deliberate, based on expected value of outcomes (how pleasurable)
Expectancy Theory
What are cravings?
Habit theory is at odds with the apparent role of conscious (albeit compulsive) decision making in the control of drug seeking behaviour
An urge or craving to smoke often accompanied relapse and drug use
Most addicts report that their drug seeking behaviour is undertaken intentionally, i.e. with a mental image of the drug driving their behaviour
A mental image of the drug, incorporating its perceived appetitive value, its stimulus characteristics, circumstances under which it might be obtained, behaviours required to obtain the drug
What is expectancy theory?
Expectancy theory proposes that behaviour is goal-directed, driven by learned beliefs about outcomes
Pavlovian stimuli (e.g., cues or signals) only elicit a conditioned response when they activate a mental representation of the expected outcome
Evidence in general human conditioning: Lovibond & Shanks (2002)
Drug conditioning: Hogarth et al. (2006) → demonstrated that expectancy awareness predicts drug-seeking behaviour
What did Hogarth et al. (2006) show about expectancy theory?
Smokers divided into two groups based on their awareness of stimulus-outcome contingencies:
Aware group: participants who recognized the association between specific cues and outcomes
Unaware group: participants who did not recognize these associations
Higher expectancy rating and seeking response for positive stimuli (A+) but only in aware group
Clear difference in expectancy following A+ versus B- in the aware but not unaware group
Expectancy plays a role in substance seeking behaviour
What are cognitive models of addiction behaviour?
If drug seeking was intentional, we’d expect a perfect correlation between craving (‘I desire a cigarette right now’) and drug use behaviour (actual smoking behaviour);
But, meta-analysis of studies to date suggests that the correlation is far from perfect
Tiffany (1990) proposed that drug users can switch between intentional and automatic modes of behavioural control
Sometimes intentional (i.e. controlled by a mental image or craving for the drug) and
sometimes controlled automatically by external drug related cues just like other S-R habits
